This invention relates to a catheter and introducer needle assembly. Catheters, particularly intravenous (IV) catheters, are used for infusing fluid, such as normal saline solution, various medicaments and total parenteral nutrition, into a patient, withdrawing blood from a patient or monitoring various parameters of the patient""s vascular system. Peripheral IV catheters tend to be relatively short, and typically are on the order of about two inches or less in length. The most common type of IV catheter is an over-the-needle peripheral IV catheter. As its name implies, an over-the-needle IV catheter is mounted over an introducer needle having a sharp distal tip. At least the distal portion of the catheter tightly engages the outer surface of the needle to prevent peelback of the catheter and thus facilitates insertion of the catheter into the blood vessel. The distal tip of the introducer needle extends beyond the distal tip of the catheter with the bevel of the needle facing up away from the patient""s skin.
The catheter and introducer needle assembly is inserted at a shallow angle through the patient""s skin into a blood vessel. There are many techniques for inserting such a catheter and introducer needle assembly into a patient. In one insertion technique, the introducer needle and catheter are inserted completely into the blood vessel together. In another technique, the introducer needle is partially withdrawn into the catheter after the initial insertion into the blood vessel. The catheter is then threaded over the needle and inserted completely into the blood vessel.
In order to verify proper placement of the catheter in the blood vessel, the clinician confirms that there is flashback of blood in a flashback chamber. The flashback chamber is typically formed as part of the needle hub. Alternatively, the introducer needle could include a notch or opening formed along a distal portion thereof so that the blood flashback can be observed in the annular space between the introducer needle and the catheter when the catheter is transparent or at least translucent. Once proper placement of the catheter into the blood vessel is confirmed, the clinician applies pressure to the blood vessel by pressing down on the patient""s skin over the blood vessel distal of the introducer needle and the catheter. This finger pressure occludes or at least minimizes further blood flow through the introducer needle and the catheter. The clinician then withdraws the introducer needle, leaving the catheter in place, and attaches an appropriate device to the catheter. Such a device can include a fluid delivery device, a PRN, a deadender cap or a blood pressure monitoring probe.
Although typical IV catheter and introducer needle assemblies generally perform their functions satisfactorily, they do have certain drawbacks. For example, the procedure for properly placing a catheter into a patient""s blood vessel can result in a significant amount of blood leakage from the catheter between the initial venipuncture and the time that an appropriate device is connected to the catheter. This blood leakage is problematic because of potential contamination to a clinician from an infected patient. This is especially worrisome because of the advent of currently incurable and fatal diseases, such as Acquired Immune Deficiency Syndrome (xe2x80x9cAIDSxe2x80x9d), which can be transmitted by the exchange of body fluids from an infected person to another person. Thus, contact with the body fluid of an AIDS infected person must be avoided.
In order to minimize blood leakage, it is known to include a self-sealing septum placed in the proximal end of the catheter hub. The septum allows the introducer needle to extend through the septum and the catheter to allow the catheter to be placed into a patient""s blood vessel. In addition, the septum allows the clinician to withdraw the introducer needle from the catheter and the septum, which then closes after the introducer needle has been completely withdrawn from the catheter hub. This arrangement does minimize blood leakage from the catheter hub. However, the use of a septum significantly increases the force that the clinician needs to exert on the introducer needle in order to withdraw the introducer needle from the catheter. In addition, if the introducer needle is located in the septum for extended periods of time, such as when the catheter is in a healthcare facility""s inventory prior to use, the septum may take a compression set about the introducer needle. This may prevent the septum from completely sealing once the introducer needle is ultimately withdrawn from the septum, which is antithetical to the use of the septum in the first place. In addition, where an introducer needle is used that includes a notch formed therein, blood leakage could still occur when the introducer needle is being withdrawn from the catheter if the septum is not properly configured.
It is therefore an object of this invention to provide an IV catheter and introducer needle assembly that minimizes blood leakage from the assembly during the insertion procedure.
It is another object of this invention to provide an IV catheter and introducer needle assembly that uses a septum to minimize blood leakage from the assembly even where a notched introducer needle is used.
It is still another object of this invention to provide an IV catheter and introducer needle assembly that uses a septum to minimize blood leakage from the assembly but that exerts a reduced drag force on the introducer needle when it is being withdrawn from the catheter.
It is yet a further object of this invention to provide an IV catheter and introducer needle assembly that uses a septum to minimize blood leakage from the assembly and that does not take a compression set about the needle so the septum effectively blocks the flow of fluid therethrough even after the introducer needle is removed from the catheter.
The above and other objects are satisfied by the IV catheter and introducer needle assembly with the low drag septum of this invention. The catheter assembly includes an adapter at its proximal end, which preferably includes at least one wing radially extending from the catheter adapter. The catheter adapter also includes a side port in fluid communication with the catheter. A septum is located in the proximal end of the catheter adapter proximal of the side port. The septum prevents any fluid from flowing into or out of the proximal end of the catheter adapter and thus diverts any fluid flowing in the catheter lumen into the side port. The septum has a hollow interior portion to minimize drag on the introducer needle as it is being withdrawn from the catheter through the septum.
The introducer needle is connected at its proximal end to a needle hub and preferably includes at least one notch, i.e. a hole or opening in the sidewall, formed therein in communication with the introducer needle lumen. The notch is formed in the introducer needle such that blood can flow into the open distal end of the introducer needle, through the lumen in the introducer needle and through the notch outside the introducer needle into the catheter lumen. Thereafter, the blood can flow through the annular space between the outside of the introducer needle and the inside of the catheter and catheter adapter and then through the side port and extension tube that extends from the catheter adapter. Preferably, the catheter, the catheter adapter and the extension tube are transparent or at least translucent. In this way, the clinician can immediately and easily visualize flashback of blood through these parts of the catheter assembly when the introducer needle has been inserted into a patient""s blood vessel.
After the clinician confirms proper placement of the catheter into the patient""s blood vessel, the clinician withdraws the introducer needle from the catheter by pulling the needle hub in a proximal direction. The septum must be long enough so that both the notch and the open distal end of the introducer needle can be located simultaneously within the septum. This ensures no blood leakage occurs when the introducer needle is being withdrawn from the catheter. If the septum is too short, the open distal end of the introducer needle could be distal of the distal end of the septum in the blood flow path while the notch could be located proximal of the proximal end of the septum. This could allow blood to leak form the catheter when the introducer needle is being withdrawn. The septum defines a hollow internal portion which minimizes drag on the introducer needle as it is being withdrawn therefrom.